JPH03257299A - Center pillar bearing/replacing construction method in multiple-connected tunnel lining - Google Patents

Abstract

PURPOSE:To improve work efficiency by building a temporary center pillar up at the combined part of covering bodies constructed at the peripheral wall of a multi-connected tunnel, then building temporary bearing pillars up on the side parts of the temporary center pillar, and removing the temporary center pillar so as to build a permanent center pillar up between extended girders. CONSTITUTION:Going with construction of cylindrical wall bodies 3, a temporary center pillar 7 is built up between the mutually opposed faces 3b of an upper and a lower branch part segment 3B. Temporary bearing pillars 5 are disposed across upper and lower pillar bearing seats provided at the branch part segments 3B so as to be built up on both sides of each temporary center pillar 7. The temporary center pillar 7 in this block is then removed, and the cylindrical wall bodies 3 are supported by the temporary bearing pillars 5, as well as girders 8 are extended to the opposed faces of the respective segments 3B so as to be fixed at the branch part segments 3B. A permanent center pillar 6 is then built up between both end parts of the upper and lower girders, and the temporary center pillar 7 is removed. Work can be thereby performed efficiently.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a temporary center pillar erected between the composite parts when lining a multiple tunnel made of a composite of excavated holes having a substantially circular cross section. Concerning the construction method of replacing the pillar with a permanent central pillar.

[Technical Background of the Invention] In recent years, a method called the double circular special cross section shield method has been used as a large cross section shield construction method for constructing large cross section tunnel structures such as underground railway tunnels.

This construction method uses a shield excavator with a structure in which multiple cylindrical shield excavators are connected to excavate the ground into a cross-sectional shape in which several approximately circular cross-sectional excavation holes are connected. A cylindrical wall is constructed by installing segments such as RC segments that are connected to each other on the peripheral wall of the excavation hole. The inner surface is covered with concrete (secondary lining), which supports the ground and forms a predetermined inner space. Usually, the composite part of the cylindrical wall body is provided with branch segments corresponding to the composite part, and furthermore, between the branch segments, a central column is installed as a support.

By the way, for example, in a subway tunnel, three shield excavators are connected horizontally to form an excavation hole, and the central excavation hole is used as a platform, and the excavations on both sides are used as a railway station. During construction, the central pillars are placed on both sides of the central excavation hole for each branch segment, and if left as they are, they will obstruct passengers getting on and off and passing through the platform. Therefore, instead of these central pillars, it is necessary to erect permanent central pillars at intervals that support the cylindrical wall but do not interfere with getting on and off the vehicle or passing through the platform.

However, an efficient construction method has not yet been developed for removing the center pillars that were initially erected for each segment and then erecting the main center pillars at predetermined intervals. The current situation is that

The present invention has been made in view of the above circumstances, and its purpose is to install permanent center pillars in place of temporary center pillars erected for each segment when lining multiple tunnels. An object of the present invention is to provide a method for replacing center pillars in lining a multiple tunnel, which enables efficient construction at intervals.

[Means for Solving the Problems] In order to achieve the above object, the present invention constructs a lining body of segments on the peripheral wall of a multiple tunnel formed by combining a plurality of excavated holes with a substantially circular cross section in a substantially horizontal direction. , After erecting temporary middle pillars for each segment between the mutually opposing surfaces of the composite part, in a predetermined section, erecting temporary support columns to support the lining body on the sides of each temporary middle pillar, The temporary center pillars are removed, then girders are extended to each of the opposing faces in this section, permanent center pillars are erected between these girders, and then the temporary support columns are removed. .

[Operation] The method of replacing the middle pillar in the lining of a multiple tunnel according to the present invention is as follows: - First, the lining body is supported by temporary support columns, and then the temporary middle pillar is removed and the permanent middle pillar is built. After the temporary support columns are installed, they are removed, making it possible to efficiently replace the permanent support columns at predetermined intervals.

In this construction method, the used and removed temporary center pillar can be reused when constructing a new cylindrical wall in front of it and erecting the center pillar.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

Figures 1 and 2 show a large cross-section excavation hole in which parts of three adjacent drilling holes LA, IB, and IC are combined using a shield excavator with a structure in which three shield excavators are connected approximately horizontally. 1 is excavated into the ground G, and its peripheral wall 2 is formed into arc plate-like segments 3A and branch segments 3 that are connected to each other.
A cylindrical wall body (lining body) 3 is constructed by lining B, and as the excavation hole 1 is excavated, this cylindrical wall body 3 is connected along the excavation hole 1 to form a subway station area. The tunnel is being constructed. In this tunnel, the central drill hole 1A is the platform, and the drill holes IB and IC on both sides are the platform.
is of the type used as a railway.

The branch segment 1-3B has a Y-shaped cross section and is disposed at two upper and lower composite portions 4 of the cylindrical wall body 3, respectively. On the R surfaces on both sides of this branch segment 3B,
A post support seat 6 for receiving a temporary support post 5, which will be described later, is integrally provided.

Next, a permanent center pillar is built into the cylindrical wall body 3 according to the present invention (the procedure of the process will be explained based on FIGS. 1 to 5).

First, as shown in FIGS. 1 and 2, as the cylindrical wall body 3 is constructed, a temporary center pillar 7 is erected between the opposing surfaces 3b of the upper and lower branch segments 3B.

Next, as shown in FIG. 3 (1), in a predetermined section,
Upper and lower support supports 6 provided on the branch segment 3B
Temporary support columns 5 are disposed across the entire length, and the temporary support columns 5 are built on both sides of each temporary middle column 7. After the temporary support columns 5 are erected in this manner, the temporary middle columns 7 in this section are removed, and the cylindrical wall body 3 is supported by the temporary support columns 5.

Next, as shown in FIG. 3(2) and FIG. 4, a girder 8 having the same width as the branch segment 3B is extended on the opposing surface of each branch segment 3B in the above section, and the branch part Fix to segment 1-3B.

Next, as shown in FIG. 3 (3), a permanent center pillar 9 is erected between both ends of these upper and lower girders 8.
Remove temporary center pillar 7. As shown in FIG. 5, the main pillar 9 has a character shape with bulging upper and lower ends when viewed from the side.
Further, the length (depth) of the upper and lower end faces is the same as the opposing surface 3b of the branch segment 3B, and it is built between the girders 6 with half protruding from both ends of the girder 8. FIG. 5 shows this state from the side.

The above steps are performed sequentially as the excavated hole 1 is formed and the cylindrical wall 3 is constructed, and the main pillars 9 are erected between the branch segments 1-3B via the girders 8 at predetermined intervals. It's getting complicated.

In the case of this embodiment, as shown in FIG. 5, the length of the removal section, that is, the girder 8, is five branch segments 3B,
The main pillar 9 corresponds to the branch segment 3B, and
It is arranged across both ends of the two girders 8 to be connected. Further, the main pillars 9 have a strength capable of supporting the cylindrical wall bodies 3 at predetermined intervals, and the intervals are as follows:
The distance will be set at a distance that will not interfere with passenger boarding and alighting or platform traffic.

With the construction method described above, it is possible to efficiently perform the work of removing the temporary middle pillars 7 and replacing the permanent middle pillars 9 at predetermined intervals with respect to the cylindrical wall body 3 . In this construction method, once the work in a certain section is completed, the temporary center pillar 7 that was used and removed at that time is reused when constructing a new cylindrical wall in front of it and erecting the center pillar. can.

[Effects of the Invention] According to the method for replacing the middle pillar in lining of multiple tunnels of the present invention, segments are formed on the peripheral wall of multiple tunnels formed by combining a plurality of excavated holes with approximately circular cross sections in a substantially horizontal direction. After constructing a lining body according to After erecting the pillars, remove the temporary middle pillars, then extend girders to each of the opposing faces in this section, erect the permanent middle pillars between these girders, and then install the temporary supporting pillars. Since it is characterized by being removed, it becomes possible to efficiently perform the work of replacing the main pillars at predetermined intervals. Moreover, this construction method has the advantage that the used and removed temporary center pillar can be reused when constructing a new cylindrical wall body in front of it and erecting the center pillar.

[Brief explanation of drawings]

1 to 5 are diagrams showing an embodiment of the present invention, in which FIG. 1 is a front view of a cylindrical wall with temporary central pillars installed, and FIG. 2 is a view of the structure shown in FIG. ■-■ line arrow view, Figure 3 (1)
~ (3) are diagrams explaining the procedure of the construction method, and Figure 4 is Figure 3 (
2) IV-IV line arrow view, Figure 5 is the ■ of Figure 3 (3)
-V line arrow view. 1, LA, IB, IC...Drilling hole, 2...
... Peripheral wall, 3... Cylindrical wall body (lining body), 3A...
... Segment, 3B ... Branch segment, 3b ... Opposing surface, 4 ... Composite part, 5.
...Temporary support pillar, 7...Temporary middle pillar, 8...
...Girder, 9...Permanent center pillar, G...Ground.

Claims (1)

[Claims] A segment lining is constructed on the peripheral wall of a multi-tunnel made up of multiple excavated holes with a roughly circular cross section in a roughly horizontal direction, and temporary center pillars are erected for each segment between the opposing faces of the composite part. After that, in a predetermined section, temporary supporting columns to support the lining are erected on the sides of each temporary middle pillar, the temporary middle pillars are removed, and then girders are installed on the opposing faces in this section. A replacement method for center columns in the lining of multiple tunnels, characterized by extending the construction, erecting permanent center columns between these girders, and then removing the temporary support columns.